This page has some general animal videos. Check the pages below for videos on specific phyla.
Animals have many different ways to determine gender. http://ed.ted.com/lessons/sex-determination-more-complicated-than-you-thought
Everything you want to know about animal penises. http://www.ted.com/talks/lang/en/diane_kelly_what_we_didn_t_know_about_penis_anatomy.html
Here’s a clip on Nemertean worms (Phylum Nemertea) and Echinoderms. http://www.youtube.com/watch?v=HG17TsgV_qI